Electric clock system



Jan. 3, 1933. s. F. HARTER 1,392,699

ELECTRIC CLOEJKSYSYTEM Filed May 2. 1929 z'sneets-sneet 1 Jan. 3, 1933. F, H RTE 1,892,699

ELECTRIC CLOCK sYsTEfi Filed May 2, 1929 2 Sheefs-Sheet 2 aee'ondariy L'Zocks 5 magnets or other clocks,

erent characteristics (such ..of current) and at difierent time of impulses. v

advanced to synchronlsm in various ways,

Patented Jan. 3, 1933 enonon 1'. names, or srnmermnn,

nnncrarc rum comm,

CONNECTIGU OI SPRINGFIELD,

EASSA GHUSETTS, ASSIGNOB 1'0 'lHE STANDARD MASSACHUSETTS, A CORE ORANGE O1 ELEGI'B-IC Application Med 1., a, aae. Serial no. asasao.

This invention relates to electric clock systems in which impulses are transmitted from a master clock or other control apparatus to secondary clocks having electromeans for advancing the to the im ulses, andv arhands in response ticularly to systems in whic hands are'advanced in directresponse to the impulses rather than indirectl throu h a rewinder which stores energy erived rom the impulses for driving the hands continuously.

Objects of system the invention areto provide a if too fast or too slow, is corrected at predetermined intervals, as the end of each hourly cycle, and without interference with the normal 0 1 eration of another secondary clock in e system, which requires only a single circuit '(two wires or one wire and (ground) between the control apparatus an the secondary clocks while permitting the use of a multiple .nomical in construction and reliable and durable in use, and which is generally superior to prior systems of this character.

The invention is applicable to control aparatus for transmitting impulses of "di alternatingcurrent and impulses which also in kind intervals voltage impulses or direct current impulses or differ both in magnitude and a (such as once per hour and once r minute respectively) together with secon a clocks:

normally driven by one kind of impu ass and periodically synchronized by the other kind Whi e slow secondaries may be preferably a series of fast impulses are trans-- mitted thereto during the period between the synchron zing or starting impulse and the next preceding normal or: drivin 'im-- pulse, thereby to bring any of the secon aries which may be slow into position to bestarted in synchronism with all the other secondaries when-the starting impulse (of high voltage or alternating currentor otherwise I difierent) is transmitted.

the secon ary.

. minute throu in which any one of the secondary-- for example at automatically circuit if desired, which is simple and ecoa startin as high and low ,menjtsare shown in the accompanying By makingthe periods of time between the starting impulse and the first-and last normal gether constitute a series of regular transmitted'at constant predetermined time intervals throughout recurrent cycles (every hout hourlycycles, e. g.) the starting impu se involving merely a change 1n the character (magnitude or kind of current) of impulse and constituting an altered driving impulse of the aforesaid regular scries. I

.The secondaryclocks are characterized by an electromagnet or other means for advancinfisthe hands min-response I the drivin imp es (minute impulses in he aforesai ex:- ample) until thehands reach predetermine positions (with the minutehands in thew minute positions, for then renderingeffective further to impulse 'nd of current) is received. If a secondary be slow the aforesaid fast im ulses also function as driving impulsesjust fore the starting impulse, initiates a new cycle or conditions the secondary clocks for a new the aforesaid means inadvance the hands-until different cycle. 1

For the, purpose of illustrating the ginus 'of the invention typical concrete diin? in which ig. 13.98, diagram of the system; Fig. 2 is an elevational view pf the timer of the master clock;

" Fig. 3 is an elevational viewof a secondary clock movement differing somewhat that shown in .Fi .1, and

' Fig. .4 is a iagram similar Fig. 1 showing-a modification using rect and alternating current. p

The particular embodiment of the invention shown in Fig. 1 comprises a master cl having a circuit closer. 1 which closes circuit 'at regular intervals suchas-onee per minute,

another circuit closer 2 whichcloses circuit at more frequentintervals such as once per (of diiferent voltage 011 e. g.) together with means draw- 86 second, a circuit controller 3 normally standing in the neutral position shown in Fig. 1 and closing either circuit 4 or circuit 5 when moved to its lower or upper positions respectively, a timer 6 for controlling the circuit closer 3 and turning at a constant speed, preferably one revolution per hour, an electromagnet 7 for controlling switch 8, the switch normally engaging contact 9 and being lifted into engagement with contact 10 when the magnet 7 is energized, an electromagnet 11 controlled by the switches 1 and 2 for closing the switch 12 when energized, and a transformer having a primary 13 connected to a source of alternating current through switch 12 and a secondary 14 connected to a rectifier 15 through switch 8, the rectifier 15 being connected across the entire secondary when the switch 8 is in upper position and being connected across only a part of the secondary when the switch is in the lower position.

The periphery of the timer 6 engages the switch arm 3 through a lug 16 which is held against the timer by spring 17. The periphery is provided with a cam projectlon 18 which depresses the switch arm 3' into contact with the terminal of circuit 4 for a brief interval during each revolution of the timer, as for example from fifty-nine minutes and ten seconds to fifty-nine minutes and forty seconds. Immediately following the projection 18 is a depression 19 into which the lug 16 is moved by spring 17 as soon as the projection passes, preferably just before the master clock reaches the sixty minute position, thereby to close circuit 5 while the minute circuit closer 1 sends the sixtieth minute impulse. The-timer 6 is also provided with any number of depressions 20 and 21 to permit the circuit closer 3.to close the circuit 5, through electromagnet 7 .and source 22, at intervalsintermediate the sixtyminute positions, for example while the circuit closer 1 sends the nineteenth and thirtyninth minute impulses.

. and

The angular positions of the projection 18 the depressions 19, 20 and 21 are indicated in Fig. 2 where the numerals at the ends of the radial lines indicate the times when the respective points of the circumference of g the timer intersected by the radial lines pass the lug 16 on arm 3.

The secondary clock movement diagrammatically illustrated in Fig. 1 comprises an electromagnet D for wheel 23 through a pawl 24 on arm25 pivoted at 26. Arm 25 carries a stop 27 for engagement with a second rat chet wheel 28 fast to shaft 29 upon which the ratchet wheel 23 is fastened to prevent overthrow by pawl 24, a pawl-29' pivoted at 30 and engaging with ratchet wheel 23 preventing retrograde movement of the ratchet wheels. Fast to shaft 29 is an arm 30 for engagement with an driving the ratchet insulating lug on a switch spring 31 normally engaging contact 32 and moved by arm 30 into engagement with contact 33 when the secondary clock reaches a predetermined to the secondary clocks, the switch 8 standing in the lowermost position so that these impulses are of comparatively low voltage (for example six volts). With switch 31 at the secondary clock in upper position these impulses are transmitted to the electromagnet D to advance the secondary hands through a one-minute. interval at each impulse. Between the fifty-nine and sixty-minute positions of the master clock the switch 3 is depressed to connect the seconds impulse circuit-closer 2 in circuit with the electromagnet 11, thereby to send impulses once per second to the secondary clocks duringta part of this minute, for example from fi y-nine minutes and ten seconds to fifty-nine minutes and forty seconds, thereby rapidly'to advance to the sixty-minute position any one or more of the secondary clocks which may be slow.

In this connection it is noted that in this and the following illustrations the secondary clocks are intended to advance from their fifty-nine minute positions to their sixtyminute positions when the master clock reaches its fifty-nine minute position (and likewise at every other minute position) so that the secondary clocks, if running normal- 1 are never behind the master clock; .although it will of course be understood that the secondaries might be adjusted to advance to each new position only when the master clock has reached that position.

When the-secondary clocks have reached the sixty-minute position, the resistance 37 at each secondary is included in circuit as illustrated at the bottom of Fig. 1, this resistance being suflicient to render the low-voltage magnet D. In the case of those secondary clocks which are on time the resistance 37 will be included in circuit on the fifty-ninth impulse of the minutecircuit closer 1. In the case of those secondary clocks which are too fast the resistance 37 will be included in circuit before the master clock has depressed the switch 3, so that all succeedin impulses by either the minute switch 1 or t e seconds imin the sixty-minute position, when the ample 12 volts) pulse switch will be ineffective to actuate the electromagnets D until the sixty-minute impulse is transmitted. Those secondary clocks which are too slow will be advanced to the sixty-minute position by the seconds impulse switch 2 as above described.

With the hands of'all the secondary clocks timer 6 reaches the sixty-minute position the lug 16 on the switch 3 moves into the recess 19, thereby closing the circuit of electromagnet 7 to lift switch 8 into engagement with contact 10 whereupon the entire secondary 14 is connected to the rectifier 15. Thus when the minute hand 1 energizes the electromagnet 11 to close switch 12 at the end of the sixtieth minute, an impulse of higher voltage (for exis transmitted to the secondthe electromagnets D of which are ary clocks, h

t ese adjusted to respond to impulses through hands of the secondary clocks are started on a new hourly cycle by this high voltage impulse, and after the hands have moved to the oneminute portion the switches 31 are permitted to spring upwardly into engagement with contacts 32, thereby rendering the electromaga armature with :47 fast to the shaft 29', By connecting the.

nets D responsive to the normal impulses of lower voltage. Af

ter the high voltage impulse is transmitted by the master clock the lug 16 rides out of the recess 19, thereby restoring the switch 3 toneutral position' and permitting the switch 8 to move back against contact 9. The normal low voltage impulses are then transmitted continually for fiftynine minutes except at the nineteen and thirty-nine minute positions when high voltage impulses are transmitted by providing the additional recesses ondary clock which failed to respond-to the sixty-minute impulse of high voltage (or which failed to receive the impulse due .to current interruption or other cause) need not wait a full hour for another starting impulse. Normally ,the secondary clocks will of course respond to the nineteenth and thirty-ninth minute im ulses of high voltage as'they do to the low vo tageimpulses I 1 Instead of providing the secondary clocks with a single magnet D and-switch 31 they may be provided with two magnets as shown in Figs. 1 and 3, the magnet D functioning in the same way as magnet D and the magnet S serving to stop the clock movement in the sixty-minute position by providing its a stop 46 in the path of arm two magnets and D in series as shown in 'Fig. 1 and adjusting the windin'gof magnet S so that it will respond only to high voltage the clock movements will remain age impulse causes electromagnets S to move the stops 46 out of the paths of the arms 47, the same higher voltage the resistance 37. Thus the 20 and 21, so that any secrent which passes through D. and 5.

high voltage impulse which energized magnets S also energizing magnets D' to advance the clock movements one step so that the arms 47 will pass the stops 46 before the latter drop back. The modification using startin impulses. of alternatin current shown in i 4 is in large part 1i e the arrangement s own in Fig. 1 and inasmuch as corresponding parts are correspondingly designated they need not be described again. In this modification the switch 12 controlled by relay 11 is placed in the circuit of the secondary 14 instead of the circuit of the rimary 13; and the relay 7 controls a double-pole switch 8' instead of a single pole-switch 8. In the lower normal position of the switch 8', with the switch in contact with 9 and 9, the circuit L is connected to the rectifier 15 so that an impulse of direct current is transmitted to the secondary clock each time the switch 12 is closed. The upper contacts 10 and 10' of the switch 8 are connected directly to the secondary 14 so that when the switch 8' is in upper position closure of the switch 12 transmits to line L an impulse of alternating current. The right-hand secondary clock 0 Fig. 4 is like that shown at the bottom of Fig. 1 ex-' ,cept in that a condenser 37 is substituted for the resistance 37. The left-hand secondary shown in Fig. 4 may be constructed as shown in .Fi 3 and connected in a branched circuit with the-driving magnet D in one branch and the-resetting or synchronizing magnets S in the other branch in series Wltha con-' denser 37 As in Fig. 1 the secondary clocks become unresponsive to the normal driving impulses when they reach the 59th minute position, moving on to the next position only in response to an impulse of alternating curthe condenser 37 From the fore oing it will be evident that th s invention a ords a remarkably simple and reliable clock system. For example the secondary clocks may be fully controlled with asingle-circuit magnet or magnets in contradistinction to magnets having a plurality of windings and requiring multiple circuits such as difierentially wound magnets heretofore used. Moreover, the secondaries may be synchronized by a momentary starting impu se, preferably lasting only a small fractionof a minute, whereas prior systems have required the application of current for as long as fifteen minutes. While the impulse of difierent kind is herein referredto as a starting impulse inasmuch as it initiates a new cycle, it may of course be re arded as the last impulse of each cycle,

especially when the secondary clocks are adjusted to movefrom their fifty-nine-minute positions to their sixty-minute positions in response to the sixty-minute impulse instead of the fifty-nine-minute impulse of the master clock.

Certain features of the system 5 ticularly concerns the means, such as typified by notches 20 and 21 in controller 6, operative during each cycle of the master clock or other control means for restarting any st 0pped' clock which fails to start at the beginning of a cycle before it has lost so much time that it can not be accelerated to correct time by the rapid impulses transmitted near the end of the cycle.

at the control station for sending driving impulses to the secondary clocks during each cycle of the secondary hands and a startin impulse at the beginnin of each cycle and again after a series of riving impulses of t e same cycle, and means at the secondary clocks for advancing the hands in response to the driving impulses until the hands reach the end of a cycle and then startin a new cycle in response to a. startin impu Signed by me at Sprin eld, Massachusetts, this 30th day of April, 1929.

GEORGE F. HARTER.

-- means for producirg fast impulses during a se,

I claim: I i 1. An electric clock system comprising sec- 80 ondary clocks of the Impulse type, control means operable through a predetermined cycle for intermittently advancing the clocks through corresponding cycles, said control means sending one kind of driving impulses 85 during each cycle and a startin impulse of different kind at the end of eac cycle, stop means in each clock for stop ing its advance at the end of its cycle if it he too fast, said stop means being responsive to said starting 90 impulse to restartthe clock when the control means reaches the end of its cycle, the control means then advancing the clock with driving impulses during themaj or portion ofthe cycle, and a controller for sending a 0-) starting impulse not only at the end of each cycle but also after a series of intermediate W 1 driving impulses so that any stopped clock which fails to respond to the first starting impulse will receive another such impulse be- 139 for? it has lost time corresponding to a full cyc e.

2. An electric clock system comprising means for continually transmitting regular 40 impulses at constant predetermined intervals ll;

throughout recurrent cycles, means for changing the character of'one of said impulses at the same interval of each cycle, and short period prece mg said latter impu said second means also changing the character of another impulse during each cycle after a series of regular impulses.

3. An electric clock system comprising 0 line connections, control apparatus for trans- 115 mitting over said line connections cycles of regular impulses at constant predetermined intervals, certain impulses of each cycle dif-' fering from the others and alternatin there- 6 with a plurality of times during eac cycle,

, and fast impulses preceding only one of the different impulses of each cycle, and secondary clocks each comprising hand advancing means responsive to the regular and fast impulses until the hands reach predetermined 12 positions and then responsive only to said different impulse.

4. An electric clock system comprising a control station having circuit connections 6 with secondary clocks, transmitting means 

